A German rider took the Tour de France lead with epic an solo attack on a bike he borrowed from a teammate in the middle of the race

Germany's Tony Martin took the lead in the Tour de France on Tuesday by attacking late on stage four on an ill-fitting bike that he borrowed on the fly from one of his teammates.

On the last of several cobblestoned sections, Martin got a flat tire. Normally he'd just grab his spare bike from his team's car, but the car was stuck in traffic behind the select group of about 35 seclect riders he was racing with.

Martin's teammate Matteo Trentin was with him at the time of the puncture and told him to just take his bike.

Trentin's bike is a few centimeters larger than Martin's and the brakes are reversed - the rear brake is on the left side of the handlebar and the front on the right.

But it didn't matter as Martin pulled out one of the biggest wins of his career after attacking with 3.3 kilometers to go to the finish line, just holding off Paris-Roubaix winner John Degenkolb by 3 seconds.

With the win he donned his first yellow jersey, one of cycling's most coveted prizes.

He said it was "super difficult" to pull it off as he was trying to deal with the borrowed bike and his rivals for stage victory.

"I think I put out more watts than I ever did," said an exhausted and emotional Martin.

Martin now leads the Tour by 12 seconds over previous leader Chris Froome, the Kenyan-born UK rider who won the 2013 Tour.

The Tour started on July 4 in Utrecht, the Netherlands, and finishes in Paris on July 26.

You can watch the finish in the video clip below:

More to come.